Selectively gated through single



March 17, 1970 o, CROWTHER ETAL Re. 26,821

STEPPING-TUBE MULTIPLE-STORE CIRCUIT EMPLOYING PLUHAL COUNTER CHAINS SELECTIVELY GATED THROUGH SINGLE INTERSTAGE GATING CHAIN Original Filed Dec. 19, 1963 2 Sheets-Sheet 1 J W I 06 E r H I It 5| L 30 NE n w w L O u m we 0 59 NE mm no ox mw u we 00 m AT a 5 I l I I I Iv q lw fit 4 n. 4 m. #2 iiii s 0 DE o vl im iilllllll I i IT .E 5 7 no INVENTORS GERALD O. CROWTHER BY GRAHAM F. JEYNES AGENT Much 17, 1970 a. o. gnaw-raga lTAL Re. 26,821

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un 3 h 9. MM nE S AGENT United States Patent 26,821 STEPPING-TUBE MULTIPLE-STORE CIRCUIT EMPLOYING PLURAL COUNTER CHAINS SELECTIVELY GATED THROUGH SINGLE INTERSTAGE GATING CHAIN Gerald Otlley Crowther and Graham Frank .Ieyues, Cheam, England, assignors, by mesne assignments, to US. Philips Corporation, New York, N.Y., a corporation of Delaware Original No. 3,308,337, dated Mar. 7, 1967, Ser. No. 331,678, Dec. 19, 1963. Application for reissue Feb. 3, 1969, Ser. No. 802,286 Claims priority, application Great Britain, Dec. 19, 1962, 47,958/62 Int. Cl. Hlllj 17/36 US. Cl. 31584.5 6 Claims Matter enclosed in heavy brackets [1 appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additious made by reissue.

ABSTRACT OF THE DISCLOSURE A group of chains of cold cathode stepping tube counting circuits and a chain of gating circuits for transferring counting pulses between tubes in a chain, and a set of switches for connecting the gating chain to a desired chain of the tube group, thereby isolating or decoupling the remaining chains.

This invention relates to counting-circuits and more particularly to multiple chains of cold-cathode steppingtube counting-circuits which may be used in small computing machines.

The invention provides an arrangement whereby a plurality of counting circuits can be controlled by a single series of interstage gating circuits and thereby avoid the necessity of providing separate interstage gate circuits for each counting-chain.

The term stepping tube is herein used to define a tube having an electrode assembly comprising a common electrode, a plurality of switching electrodes and a plurality of further electrodes, wherein a stream of electrons and ions may be caused to travel between the common electrode and one of the further electrodes and wherein one end of the stream may be caused to move from one to another of the further electrodes in a predetermined sequence by the application of suitable potentials to the switching electrodes.

Usually, the central electrode is circular and functions as an anode, the other electrodes being arranged in a circular row, and when in use, being returned to a potential more negative than that to which the anode is returned. These other electrodes thus may correctly be regarded as cathodes; however, each position in the tube usually has associated with it three or four of these electrodes and it is convenient to distinguish them by referring to those on which the glow discharge rests between pulses as main cathodes or cathodes and to refer to the other electrodes as guide electrodes" or guides.

In known stepping tubes the transfer of the discharge from its rest position on'one cathode to its rest position on the next cathode is thus effected by means of a plurality of guide electrodes; where there are two guide electrodes between adjacent cathodes the guide next to the cathode in the direction of rotation of the discharge is usually termed the first or A guide and the next guide again in the direction of rotation of the discharge, is termed the second or B guide. Throughout this specification the terms A guide and B guide will be used. In these known tubes all the A guides are usually connected together or commoned inside the envelope and all the "ice B guides are similarly connected together; in operation the discharge is transferred in its entirety from its rest position on one cathode to an A guide, then from the said A guide to a B guide and finally from the B guide to the next cathode.

According to one aspect of the present invention the counting arrangement includes a plurality of countingchains wherein each counting-chain comprises a chain of cold-cathode stepping-tube stages. A series of interstage gate circuits are arranged so that a gate circuit can be connected between each pair of successive stepping-tube stages, and means are provided for so connecting the gate circuits into a selected chain. Further means are connected to the chains for inhibiting the application of stepping pulses to one set of all stepping-tube guide electrodes in the unselected chains.

An embodiment of the invention will now be described with reference to the accompanying diagrammatic drawings wherein,

FIGURE 1 illustrates a first embodiment, and

FIGURE 2 illustrates a second embodiment.

Referring to FIGURE 1 this shows three stepping-tube counting chains of. a general arrangement substantially similar to that described in our copending US. application Serial Number 331,676, filed December 19, 1965. Only part of each chain is shown and these parts include stepping-tubes Vtl and Vhl of the tens and hundreds" stages respectively for the first chain, together with tubes Vt2 and Vh2 for the second chain and tubes Vt3 and Vh3 for the third chain. Interstage gates, of which the hundreds gate Gh and the thousands gate Gth are shown in part are provided for association with each countingchain: these gates are the same as those described in detail in the above-mentioned specification.

The B guides GB of the stepping-tubes in all chains are connected to a common B pulse line BPL but the A guides GA in each stage are returned through a diode D1 to an A pulse line APL associated with the appropriate chain so that there are three A pulse lines, one for each chain, to which the guides GA are returned through respective diodes D1. Each stage in each chain is also connected through a respective diode D2 to the output of the common interstage rate preceding the stage so that this common gate is thus connected through respectivediodes D2 to the guides GA of the appropriate tube in each chain.

We thus have all the B guides GB connected to a common pulse line while the A guides GA are connected to individual pulse lines; in order to associate any selected counting-chain with the interstage gate circuits it is necessary that A pulses can be applied to the A guides of the selected chain while the A guides of the other chains are maintained at such a positive potential as will prevent the discharges in the tubes of these chains from stepping onto any of the A guides. This is eifected by means of a series of switches F of which there is one, F1, F2 or F3, for each chain; each switch F has contacts, indicated on FIGURE 1 by the subscript p, which when closed apply A pulses from the common A pulse line to the A pulse line of the appropriate chain. In order that when any of these contacts is open the A guides of that chain are returned to a suitable positive voltage, a capacitor C3 of the order of 0.1 ,uf. is inserted in the common A pulse line between the A pulse source and the switches F, and the A pulse line of each chain is returned through a 10K ohm resistor R11 to a 55 v. positive source.

It is a further requirement that the count stored in each chain should neither affect nor be affected by either the count storeddn another chain or the process of counting in another chain. This means that any voltage appearing at the ninth cathode K9 of any chain should not affect the voltage at the K9 cathodes of the corresponding stages in other chains and also means that any varia tion in such voltage occurring during counting in one chain should have no effect upon the other chain. To this end, the K9 cathode of corresponding stages in each chain are commoned not directly but through respective diodes D each of which is connected to the base of transistor Trl in the interstage gate. Each cathode K9 has Connected to it a diode D6 as described in the abovementioned specification and in each chain these diodes are returned to a common line which can be connected to either a zero voltage source or a 4 v. negative source. Each cathode K9 is also returned through a 1M ohm resistor R12 to a zero'voltage line: with the arrangement as shown in FIGURE 1 all the diodes D6 are returned through bias" contacts Flb, F2b and F3b to a 4 v. negative source: in this condition the voltage at each ninth cathode K9 is held at 4 v., and if one chain is then switched into a counting condition as described below and counting is caused to take place in that chain, then any positive voltage appearing at the cathode K9 of any tube in that chain will not aflect the voltage of 4 v. which is applied through the diodes D6 to the K9 cathodes of the tubes of the other chains.

Consider now the operation of counting into a particular chain, for illustration the first that is the upper chain in FIGURE 1. Switch F1 is operated to select this chain and pulse contacts Flp connect the A pulse line of the chain to the A pulse source. The bias contacts Flb remove the 4 v. bias from the diodes D6 in the chain and return these diodes to a zero voltage source so that in each stepping-tube of the selected chain where the discharge is not on K9 the K9 voltage will be clamped at about 3 v. by the emitter-base diode of Trl. If counting is now allowed to proceed in this chain then when the discharge reaches the K9 of, for instance Vtl then as the diode D6 is now returned to a zero voltage line the voltage at this cathode will rise from -3 v. to zero volts. This zero voltage is now applied through D5 to the base of Trl in the gate Gh and as the emitter of this transistor is returned to a negative source of 2.5 v. then this transistor will be cut off. The effect of cutting off this transistor and the operation of the gate circuit is described in detail in the above-mentioned specification.

However, although the voltage at the base of Trl has been raised to zero, this voltage will not be passed to the K9 cathodes of Vt2 or Vt3 because these cathodes are returned, each through a respective diode D6, to a 4 v. source and their associated diodes D5 will thus be nonconducting. When the discharge leaves the ninth cathode K9 of Vtl then the voltage at the base of Trl will fall to about 3 v. which however is still positive with respect to the 4 v. bias applied to the second and third chain so that the diodes D5 associated with Vt2 and Vt3 will remain non-conducting.

If the discharge on Vt2 or W3 is on the K9 cathode this cathode will still be held at 4 v. through diode D6; the cathode current will flow through D6 to the 4 v. negative line.

To provide a carry facility an interstage coupling circuit from each gate to the next is provided by resistor R7 and capacitor C10 as described in more detail in copending U.S. application Serial No. 331,677. If a selective read-in" facility is provided as described in that specification then the junction of these two circuit components will be taken through suitable switch contacts to the pre-pulse line; if such a facility is not required however then the resistor R7 may, if desired, be dispensed with leaving only the capacitor C10 as described and illustrated in copending U.S. application Serial No. 331,676.

In the embodiment just described only the A guides are switched so that on the arrival of B pulses along the common B pulse line all tubes in the unselected chains will step back to a B guide and will then, at the end of the B pulse, step onto the cathodes on which the discharge originally rested. The arrangement is however rather expensive in diodes and in a second embodiment illustrated in FIGURE 2 all the A guides are returned to a common pulse line whilst the B guides are switched. Referring to FIGURE 2 it will be seen that at each stage only one pair of diodes D1 and D2 is necessary for all chains; it is no longer necessary to discriminate between the A guides of one chain and those of the others because the discrimination is ellected by switching the B guides. The output from each gate is applied through a diode D2 to the commoned A guides GA of that stage in all chains, and from those commoned guides a diode D1 is connected to the common A pulse line.

The B pulse source is applied from a common pulse line through a capacitor C4 of the order of 0.1 i. to the pulse contacts of the three switches F and the B pulse line of each chain is returned through a 10K Ohm resistor R13 to a volt positive source; the bias con- [acts of each of the switches F are arranged in the same manner as already described and illustrated in FIGURE 1. The input circuits of each gate are identical with those described above and the function of the diodes D5 and D6 in each stage is the same as that already described. When a discharge is on a ninth cathode K9 of a stepping-tube in the selected chain the next A pulse will be applied to tubes in the corresponding stages in the other chains so that all will therefore step on to the next following A guide each time an A pulse is applied along the common pulse line; at the end of this A pulse the discharges in the unselected chains will step back to the cathodes upon which they rested but this will have no effect on the gate circuits because of the blocking func' tion of diodes D5 described above.

In both the circuits described above transistor Tr2 is associated with one or more diodes D2; however, as described in U.S. application 331,676 and U.S. application 331,677 a high voltage transistor may be used for Tr2 in which case the appropriate diodes D2 can be omitted in a manner substantially the same as that de scribed in those specifications.

What we claim is:

1. An electronic counting-arrangement comprising a common pulse-line for supplying counting pulses, a plurality of counting chains each comprising a chain of coldcathode stepping-tube stages of successively higher order, a chain of interstage gating-circuits, means for connecting the chain of gating circuits into a seleced counting chain to provide a gating-circuit between each pair of successive stepping-tube stages of the selected counting chain, and means for causing only the stepping-tubes of the selected chain to respond to counting-pulses supplied to all the counting-chains from the said common pulseline.

2. An electronic counting-arrangement as claimed in claim 1 comprising means for applying negative-going counting-pulses to guides of all stepping-tubes in all the chains, means for causing attenuation of counting pulses at the guides of stepping-tubes in the unselected chains, attenuating means in each gating circuit to attenuate counting-pulses at the guides of. the immediately-succeeding stepping-tube stage of the selected chain, and means in each gating circuit responsive to an output condition in the immediately-proceeding stepping-tube stage of the selected chain to render said attenuating means inoperative and thereby to provide throughout the counting-chain a carry facility between each pair of successive steppingtube stages.

3. An electronic counting-arrangement as claimed in claim 1 wherein the stepping-tubes are of the two guide type, and wherein the attenuating means in each gating circuit is operable to attenuate only pulses applied to the said first guides.

4. An electronic counting-arrangement as claimed in claim 3 comprising a pulse-line for each counting-chain, a plurality of first diodes in each counting-chain connected one between the first guides of each stepping-tube and the pulse-line of the chain, a plurality of second diodes connected one between the first guides of each corresponding stepping-tube stage in all the counting chains and the gating circuit preceding the said corresponding stepping-tube stages, means for supplying counting-pulses to the pulse line of the selected counting-tube chain to cause counting only in the selected chain, and means in each gating-circuit responsive to the output from a preceding stepping-tube stage to elfect a carry" by permitting the first diode in the succeeding stepping-tube stage to fully conduct counting-pulses from the selected pulse line to the first guides of the said succeeding steppingtube stage.

5. An electronic counting-arrangement as claimed in claim 4 comprising a second, common, pulse-line for sup plying pulses to the sets of second guides of all steppingtubes in all counting-chains.

6. An electronic counting-arrangement as claimed in claim 3 comprising a first, common, pulse-line for supplying pulses to the sets of first guides of all stepping tubes in all counting chains, a second pulse-line for each separate counting-chain, means connecting the second pulse-line in each counting-chain to the second guides of the stepping tubes of that counting-chain, means connecting the first guides of each of corresponding steppingtube stages in different counting-chains to a corresponding gating-circuit to enable each gating-circuit to control counting-pulses supplied to the first guides of corresponding stages in each counting-chain, and means for supplying counting-pulses to the second pulse-line of the selected counting-chain to cause counting only in the selected chain.

References Cited The following references, cited by the Examiner, are

of record in the patented file of this patent or the original patent.

UNITED STATES PATENTS 4/1962 Heiser 328154 4/1963 Buck 328-154 US. Cl. X.R. 3285 1, 152 

